1. Field of the Invention
This invention relates to a washing machine, more particularly to a spin tub for a washing machine which is installed in a water container in order to dehydrate the laundry.
2. Description of the Prior Art
FIG. 1 is a sectional view for showing the construction of a conventional washing machine with a spin tub installed.
Referring to FIG. 1, a washing machine 100 includes a main body 110, a tub 120, a spin tub 130, a pulsator 140, and a driving device 150. The main body 110 resiliently supports the tub 120 therein through a resilient supporting mechanism (not shown). The spin tub 130 made, for example, of plastic is arranged in the tub and has on its peripheral wall a plurality of perforation for dehydration of the laundry. The pulsator 140 is disposed in the lower portion of the spin tub 130 to be rotated in clockwise and counterclockwise directions according to a driving force which is provided by the driving device 150. The driving device 150 includes a driving force-generating motor 1501, a clutch 1502 which can connect or disconnect the driving force of the motor transmitted through a pulley 1503, and a driving shaft 1504 which transmits the driving force of the motor 1501 to the pulsator 140 or the spin tub 130.
Therefore, when the laundry(not shown) has been put into the spin tub 130 of the washing machine 100, and the motor 1501 is operated by a control program or data set by a user, the driving force of the motor 1501 is transmitted to the clutch 1502 by way of the pulley 1503.
The clutch 1502 transmits the driving force of the motor 1501, which is transferred through the pulley 1503 during washing or spin drying and the like, to the pulsator 140 or to the spin tub 130 through the driving shaft 1504.
In other words, during the washing process, the clutch 1502 is operated for transmitting the driving force of the driving device 150, and the washing machine 100 measures an amount of the laundry by operating the pulsator 140 in clockwise and counterclockwise directions.
When the amount of the laundry is measured, washing water is supplied by a tap (not shown) according to the amount of the laundry, and the driving device operates the pulsator to be rotated in the clockwise and counter clockwise directions. A friction force and/or turbulence generated by the operation of the pulsator 140 among the washing water, laundry, pulsator 140 and the spinning tub 130 performs washing the laundry.
The clutch 1502, during a spin cycle, transmits the driving force of the motor 1501 to the spinning tub 130 so as to rotate the spinning tub 130 in a high revolution for performance of spin driving. Of course, before the spin cycle, draining is performed.
The conventional washing machine 100 so operated in the above operating process performs repeatedly once or up to several times the washing water supply, washing, draining, spin cycle, and rinsing procedures in accordance with a control program, the user's setting data or the amount of the laundry.
One example of a spin tub is disclosed in U.S. Pat. No. 4,137,735. The spin tub suggested in U.S. Pat. No. 4,137,735 includes a perforated vertical side wall, an imperforated bottom wall, and a curved wall portion connecting the perforated vertical side wall and the imperforated bottom wall with each other. The curved wall portion has a circumscribing row of holes formed thereon to thereby carry particulate matter from the spin tub during wash periods while minimizing undesirable back flow through the row of holes during spin periods of the tub.